If you're worried about polishing compound residues in the panellines, a drop of water and a cotton bud / Q-tip will remove most of it. Much better than trying to scratch it out when dry.
And yeah, it's always a pain to glue a Revell body to the chassis. That's why I mostly use white glue (the transparent drying type). You can use more than needed, and simply wipe off the excessive glue that comes out of the joint. You have to fix body and chassis with some clamps or similar for several hours, however.